Modular storage devices, such as tape libraries, can be expanded by stacking devices together. One method that has been used to connect two storage devices is to include a circuit card in the second storage device to act as a slave to a control card of the base device. The devices are also connected with a cable that takes up one of the card slots on each of the devices. Thus, at least two card slots in the second device, one for the slave card and one for the cable, are used to connect the base device to the second storage device. Two card slots are also utilized in each additional device added to the configuration. Additionally, the pins on the connectors can become damaged during manual insertion of the cable connecting the devices together.